If your wanting to get your car running correctly and keep it running correctly like factory there are some suggestions that have already been made and I will add a few more . I know it sucks spending money on things that are not go fast goodies but these are all things I feel are essential if your wanting to work on your own car, without some of this stuff you are just shooting in the dark and it will be hard for others to help with out the needed info . Once again this is all just my opinion. The bare minimum I would have is the shop manuals, dwell meter, timing light, vacuum gauge, fuel pressure gauge and a multimeter. I know this doesn't deal with your o2 sensor question directly but I wasn't sure which post of yours to put this on.
Watch these videos to understand how the computer controlled carburetor and its systems works. These are videos that gm techs were trained with at the time. This is free firsthand knowledge about your exact car.
Video 1 https://youtu.be/8jGqIBAUnMY
Video 2 https://youtu.be/vDStPuQyo_Q
Video 3 https://youtu.be/OVrvSDuFOjM
Video 4 https://youtu.be/wbscqaLYNjw
These manuals are grade A+ In my opinion and would be exactly what the mechanic would use at the chevrolet dealership in 1983 to deal with all aspects of your car. I recommend getting the electrical supplement also. Doug Roes book is decent and I recommend it but I think this manual is better overall and deals with complete car..
Timing light, I've had good luck with this one.
Innova 3568 Digital Timing Light https://a.co/d/99UkoYP
Vacuum gauge for various troubleshooting.
OTC 5613 Vacuum/Pressure Gauge Kit https://a.co/d/6fcLgnU
Fuel pressure gauge, with the various pieces, hose calmps and fuel hose I was able to use this on stock fuel line and quadrajet.. you have to break the line at carb loose but it works.
MEANLIN MEASURE 0~15Psi Stainless... https://www.amazon.com/dp/B08HRW7ZNS?ref=ppx_pop_mob_ap_share
T block 3/8" for gauge and barbs
Eaton Weatherhead 3700X6 Brass CA360 Fitting, Tee, 3/8"NPT Female https://a.co/d/4pXy1Em
Barbs you will need 2
EDGE INDUSTRIAL 3/8" Hose ID to 3/8" 45° Male Flare Straight Brass Fitting Fuel / AIR / Water / Oil / Gas / WOG (Qty 01) https://a.co/d/9zQMrn9
Threads into carb.
Midland 38-874 Brass Inverted Flare Male Swivel, 90 Degree Elbow, 3/8" Hose ID x 3/8" Tube OD https://a.co/d/4itjw7Y
Threads onto hard fuel line
EDGE INDUSTRIAL 3/8" Hose ID to 3/8" 45° Female SAE Flare Brass Swivel Connector Fuel / AIR / Water / Oil / Gas / WOG (Qty 01) https://a.co/d/3cnIBYO
LDR Industries 516F385 5' Bag Fuel Line, 3/8" https://a.co/d/1pH2Qtl
To make this:
You need a good multimeter for troubleshooting various circuits and sensors, something like this. What I listed is just an example, I like fluke but it's way overkill for most.
Klein Tools MM600 Multimeter, Digital Auto-Ranging, AC/DC Voltage and Current, Temperature, Frequency, Continuity, More, 1000V https://a.co/d/5mXw9Pk
If you are really wanting to dig in to ccc quadrajets the Doug Roe book is good but I think most would be fine with above manual but it's a good read with good info.https://www.ebay.com/itm/2248566782...r=&widget_ver=artemis&media=COPY
For ccc rebuild parts the best place is Cliff Ruggles, he also wrote a quadrajet book but it just focuses on non ccc quadrajet. He has lots of knowledge and good parts if needed.https://cliffshighperformance.com/https://cliffshighperformance.com/product/quadrajet-ccc-rebuild-kit
Thexton makes tools to help with tuning and rebuilding the ccc, they are hard to find but can usually be found on ebay from time to time. Thexton tool kit 362, 370, and 380.The tools are not necessary but they help, if you search here and at 3rd gen.org there are work arounds if you don't have toolshttps://offerup.com/item/detail/28876930
An obd1 scanner can also be useful but not needed unless really digging In. If you have a cel you can jumper and get codes that way and look them up in the above e manual. Obd1 scanners will let you get readings of sensors also.
I get lots of useful info by searching this forum. As an example I usually go to Google and type "montecarloss 3 wire o2 forum" or "montecarloss Vacuum diagram forum". I will also ask here after I've searched just to get opinions on the subject I'm working on. I'm not trying to be a smartass it's just how I do it. Also lots of good info at https://www.thirdgen.org/.
If you go to http://montecarloss.com
click on information box then click technical information there is tons of resources.
For hard to get parts I usually go to rock auto, or ebay and hope to find them. Original Parts Group (opgi ) has some sensors but they won't be cheap. Mike's Montes has lots of parts and if it's not on his site it's worth a call.